1. Field of Invention
The present invention generally relates to a display apparatus; more specifically, to a three-dimensional display apparatus.
2. Description of Related Art
With recent advancements of display technologies, the research focus has gradually shifted towards devices that can generate three-dimensional (3D) images.
FIG. 1A is an exploded view of a conventional 3D display apparatus.
Referring to FIG. 1A, a conventional 3D display apparatus 100 includes a first panel 110, a second panel 120 and a cold cathode fluorescent light source 130 (placed in order). Between the first panel 110 and the second panel 120 there is a depth D. 3D image effects are generated due to the image brightness difference between images formed by the first panel 110 and the second panel 120, coupled with human visual illusion of this scene. Observer P perceives the generated image as if the image is located between the first panel 110 and the second panel 120. This technology is commonly known as Depth-Fused 3D, or DFD.
More specifically, as shown in FIG. 1A, the image brightness values on the first panel 110 and the second panel 120 are determined by their respective cross-sectional densities. The higher the panel cross-sectional density, the higher the brightness value; conversely, the image brightness value will be lower. Due to the lower image brightness value at a first location A1 of the first panel 110 with respect to the image brightness value at a second location A2 of the second panel 120, the observer P perceives a deeper image there. The perceived image will be located closer to the second panel 120 (farther away from the observer P). Similarly, the image brightness value at a third location A3 of the first panel 110 is higher than the image brightness value at a fourth location A4 of the second panel 120. Therefore, observer P observes a shallower image there, and the perceived image will be located closer to the first panel 110 (closer to the observer P). FIG. 1B is a schematic perspective view of the first and second panels of the 3D display found in FIG. 1A. Referring to FIG. 1B, the first panel 110 and the second panel 120 each respectively includes a polarizer 111,121, an active device array substrate 113,123, a color filter 115,125, and a substrate 117,127. It should be noted that a light ray L emanating from the cold cathode fluorescent light source 130 travels sequentially through the polarizer 121 of the second panel 120, the active device array substrate 123, the color filter 125, the substrate 127, the active device array substrate 113 of the first panel 110, the color filter 115, the substrate 117, the polarizer 111, and then the light ray L enters the eyes of the observer P.
The technology aforementioned makes use of two panels (the first panel 110 and the second panel 120), where the panel transmittances of the first panel 110 and the second panel 120 are very low, at around 5%. Therefore, brightness value of the light ray L emanating from the cold cathode fluorescent light source 130 will be significantly reduced after the light ray L passes through the first panel 110 and the second panel 120. In other words, there is a significant difference between the image brightness value the observer P perceives and the original brightness value of the cold cathode fluorescent light source 130. Hence, when the need to present more brilliant images arises, the cold cathode fluorescent light source 130 must be turned quite bright, hereby significantly increasing the power consumption of the 3D display apparatus 100.